A valve assembly is, e.g., disclosed in German patent application DE 42 30 393 A1 that is comprised of a parallel connection of a spherical non-return valve and another electromagnetically actuatable valve closure member. This valve assembly suffers from the disadvantage that the construction chosen produces the effect of a high dynamic pressure and a flow cross-section that limits the flow rate in the area of the spherical non-return valve. Furthermore, the spherical non-return valve is positioned in the area of housing edges that, under certain circumstances, may also have an undesirable effect on the flow performance and the reliability of operation of the spherical non-return valve. The construction makes use of predominantly massive housing components that are complicated to manufacture.
In view of the above, an object of the present invention is to improve upon a valve assembly of the type referred to hereinabove in such a way that the shortcomings indicated are overcome in order to achieve in particular a minimum possible dynamic pressure at the spherical non-return valve and a reduced load on the supporting surfaces for the spherical non-return valve, while another objective is to ensure a maximum possible passage in the area of the spherical non-return valve in consideration of the above-mentioned criteria.